The present invention pertains to a steering tie rod for motor vehicles with at least one pipe, which is provided with an internal thread in a first direction of rotation on at least one side, is slotted in at least some areas, and into which an adjusting sleeve is screwed at the end, wherein a ball-and-socket joint housing shaft of a ball-and-socket joint present at the end of the steering tie rod is screwed into the adjusting sleeve via an internal thread whose direction of rotation is opposite the first direction of rotation, and an axial adjusting movement of the pipe relative to the ball-and-socket joint is made possible by a wrench contact surface made in one piece with the adjusting sleeve.
Such steering tie rods are used in motor vehicles especially for the steerable front wheels. As a consequence of fastening on the underside of the vehicle, they are greatly exposed to contamination and weather effects. Prior-art designs of steering tie rods for motor vehicles usually comprise a pipe in the end area of which at least one internal thread is provided. Furthermore, a slotting of the pipe end is frequently provided in this threaded area. A ball-and-socket joint housing shaft, which is made in one piece with the housing of a ball-and-socket joint, is screwed into the pipe end in the prior-art designs.
However, embodiments in which an adjusting sleeve provided with external threads is screwed into the internal threads of the pipe end have been known as well. The adjusting sleeve has in turn an internal thread, in which the ball-and-socket joint housing shaft is then received via a thread. One of the threads provided in the adjusting sleeve is a left-handed thread and the other is a right-handed thread. To make possible a movement of the components in relation to one another by rotating the adjusting sleeve, a wrench contact surface is made in one piece on the outside of the adjusting sleeve. As a consequence of the opposite threads of the adjusting sleeve, the pipe and the ball-and-socket joint are moved toward or away from each other during a twisting of the adjusting sleeve, as a result of which an axial adjusting movement of the components can be achieved.
Furthermore, steering tie rods for motor vehicles have been known, which have an adjusting sleeve, in which one or more slots are provided on one side. This leads to a number of drawbacks. If, e.g., the slot is provided on the side of the adjusting sleeve on which the wrench contact surface is made in one piece with it, the adjusting sleeve undergoes an unduly great deformation during the rotating movement. The adjusting sleeve may be destroyed in extreme cases. Moreover, there is a risk that the slots in the pipe and the slots in the adjusting sleeve will overlap, so that the penetration of water and dirt into the interior of the steering tie rod becomes possible. Failure of the entire assembly unit is ultimately to be feared due to the resulting corrosion in the interior space of the steering tie rod, which must be ruled out in such safety components.
The basic technical object of the present invention is to develop a steering tie rod for motor vehicles in which the penetration of water and contaminants is effectively prevented from occurring. In addition, a constant and uniform fixation of the ball-and-socket joint in the tubular shaft shall be achieved.
According to the invention, a steering tie rod for motor vehicles is provided with at least one pipe, which is provided with an internal thread in a first direction of rotation on at least one side, is slotted in at least some areas, and into which an adjusting sleeve is screwed at the end. A ball-and-socket joint housing shaft of a ball-and-socket joint is present at the end of the steering tie rod and is screwed into the adjusting sleeve via an internal thread whose direction of rotation is opposite the first direction of rotation. An axial adjusting movement of the pipe relative to the ball-and-socket joint is made possible by a wrench contact surface made in one piece with the adjusting sleeve. The adjusting sleeve has at least one recessed slot and a collar band fixed on the outer jacket surface, which fixes the components in their positions relative to one another.
As a result of the recessed slot provided in the adjusting sleeve in a steering tie rod according to the present invention, the wrench contact surface is a surface that is closed in itself, so that deformations during the adjusting movement of the adjusting sleeve are effectively prevented from occurring.
The preparation of a recessed slot in the adjusting sleeve has, furthermore, the advantage that, on the whole, an increase in the dimensional stability of the adjusting sleeve and consequently of the entire steering tie rod assembly unit is achieved.
A collar band or another, suitable clamping means is placed on the outer jacket surface of the pipe receiving the adjusting sleeve for fastening the components in relation to one another.
Furthermore, it is possible to design the adjusting sleeve in the manner of an adapter. This means that uniform pipe diameters and uniform ball-and-socket joint housing shaft diameters can be used for steering tie rods according to the present invention. The difference in the dimensions is compensated by means of the adjusting sleeve. It was possible to create a modular system.
Provisions are made in another advantageous embodiment of the present invention for the recessed slots to be prepared extending predominantly axially or spirally in the adjusting sleeve. In addition, the recessed slots may form, when viewed as being projected onto the geometric center line of the adjusting sleeve, an acute angle with this center line or they may extend in a mutually crossing arrangement.
Other arrangements of the recessed slots are conceivable. It is sufficient according to the present invention for preparing a single recessed slot in the adjusting sleeve. However, it is, of course, also possible to provide a plurality of recessed slots. It is possible, e.g., according to the present invention to prepare in the adjusting sleeve two recessed slots arranged diagonally opposite one another or three recessed slots arranged offset by 120xc2x0 in relation to one another.
A T-shaped geometry of the recessed slots is also within the scope of the idea of the present invention. It should be noted in this connection that both the mutually crossing arrangement of the recessed slots and the T shape of the recessed slots generate elastic areas in the adjusting sleeve, so that an optimal tensioning of the components by the collar band is made possible. To impart sufficient stability to the entire steering tie rod assembly unit, the width of the recessed slots should not exceed 2 to 6 mm. A slot width of 4 mm is especially advantageous. The longitudinal extension of the recessed slots may vary as well. However, it should be between one half and two thirds of the overall length of the adjusting sleeve according to the present invention.
Since the steering tie rod is massively exposed to splash water and other contaminants in the area of the motor vehicle close to the wheel, it is, furthermore, advantageous to provide the steering tie rod and especially the adjusting sleeve with a surface protection. This may consist of a zinc-iron coating in the known manner.
Preferred exemplary embodiments of the solution according to the present invention will be explained in greater detail below with reference to the corresponding drawings.